Final answer:
To calculate moles of oxygen in 3.5 moles of NH4KMnO4, multiply 3.5 by 4 (the number of oxygen atoms in one molecule of KMnO4) to get 14 moles of oxygen.
Step-by-step explanation:
To determine how many moles of oxygen are in 3.5 moles of NH4KMnO4, we first need to ascertain the number of oxygen atoms in one molecule of the substance. Potassium permanganate (KMnO4) contains 4 oxygen atoms. Therefore, one mole of NH4KMnO4 has 4 moles of oxygen atoms. Calculating the total moles of oxygen for 3.5 moles of NH4KMnO4, we simply multiply 3.5 moles by 4 moles of oxygen per mole of NH4KMnO4, resulting in 14 moles of oxygen.